Synthesis of biodiesel from chicken skin waste: an economic and environmental biofuel feedstock in Bangladesh

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RESEARCH ARTICLE

Synthesis of biodiesel from chicken skin waste:

an economic and environmental biofuel feedstock in Bangladesh

Hemal Chowdhury ¹&Pranta Barua²&Tamal Chowdhury²&Nazia Hossain³ &Rabiul Islam²&

Sadiq Mohammed Sait⁴&Bodius Salam¹

Received: 18 September 2020 / Accepted: 9 March 2021

#The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2021

Abstract

One of the dominating meat supply industries, the poultry chicken sector, is facing waste management concerns worldwide. Due to high oil content containment, biofuel researchers emphasized poultry waste as abundant, cheap, and high-quality feedstock for biodiesel production. Therefore, in the current study, an experimental investigation of biodiesel production from wasted chicken skin through the transesterification process has been performed. The chicken skin used in this study for biodiesel production can be used as the potential waste source for biodiesel production worldwide. Techno-economic, environmental, and sustainability analyses were also performed. During the synthesis, the reaction was conducted with potassium hydroxide (KOH), and the process yielded 48% biodiesel. The cost of electricity for providing electricity is estimated at US$0.575 per kWh when an auto- sized generator has been fueled by biodiesel. The environmental and substantiality analysis found that biodiesel is more suitable than conventional diesel as an environmentally friendly and sustainable fuel.

Keywords Transesterification . Homer Pro . Sustainability . Clean energy . Techno-economic analysis . Waste minimization

Introduction

The growth of consumption of fossil fuels correlates with population growth. Energy consumption growth contributes to higher energy demand, which results in a scarcity of energy resources. Hence, the reserves of fossil fuels are quickly de- clining (Moogi et al.2020). Besides, excessive use of these fuels plays a significant role in increasing greenhouse gas

emissions. Consequently, the need for alternative fuels for the transportation and power generation sectors has attracted interest. To resolve this issue, biodiesel has attracted attention as an attractive alternative fuel source (Shay 1993; Hossain et al.2019a,b,c). Biodiesel commonly comprises mono-alkyl esters of extensive string fatty acids that can be procured from plant-based waste biomass, microalgae (Hossain et al.2019d), oil palm trunk (Mahlia et al.2019), vegetable oils, and waste oils by using the transesterification process with the help of catalysts (Mohadesi et al.2020), but food versus fuel choices and high manufacturing costs hinder the advancement of biofuel production from vegetable oils worldwide (Izah and Ohimain 2013). Feedstock from non-food sources for alternative fuel is necessary for the development of biodiesel production in developing countries. In this case, in Bangladesh and other developing countries, chicken skin and fats are the ultimate solutions for ending food versus fuel debates. Usually, chicken skin, including fat, contains between 8 and 20% of a chicken's total weight (Méndez- Lagunas et al. 2015). During the butchering and organ removal process, the fat in the abdominal cavity usually is removed, but the subcutaneous fat in the skin is not removed (Bharat and Bhattacharya 2012).

Responsible Editor: Ta Yeong Wu

* Nazia Hossain

[email protected]

1 Department of Mechanical Engineering, Chittagong University of Engineering and Technology, Kaptai Highway, Chattogram 4349, Bangladesh

2 Department of Electrical and Electronic Engineering, Chittagong University of Engineering and Technology, Kaptai Highway, Chittagong 4349, Bangladesh

3 School of Engineering, RMIT University, 128 La Trobe Street, Melbourne, VIC 3001, Australia

4 King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia

Environmental Science and Pollution Research https://doi.org/10.1007/s11356-021-13424-5

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The poultry sector accounts for over 80% of all livestock production in the world (Tubiello2017). As the poultry sector applies intensive production methods, there has developed a concern about the treatment and disposal of poultry wastes.

Poultry meal is a significant portion of these wastes. The meal includes bones, undeveloped eggs, offal, and feathers (El Boushy and Van der Poel2013). These wastes were formerly used in animal feeds. Many authorities now only allow uses in formulated pet feed (Cheli et al.2013). Also, one of the main by-products of the poultry industry is chicken waste. This waste is generally composed of skin and abdominal fats, which are not removed during chicken meat processing, and it is rarely used in the food industry. It is usually used as animal feedstock and used in biodiesel and soap production due to its fat content (Farmani and Rostammiri2014).

Literature review

Several studies have been conducted to produce biodiesel from vegetable oil, waste animal fat, feather meal, and others (Barua et al.2020a; Hossain and Mahlia2019). The most common method to extract biodiesel is transesterification.

This process depends on several factors such as reaction time, type of catalyst, and type of solvent used (Hossain et al.

2019a). The transesterification process has been used to treat chicken fat by Awaluddin et al. (2010). The study used methanol and calcium oxide, where calcium oxide acted as a het- erogeneous base catalyst. This experiment studied the aftermath of altering the variables (temperature of the reaction process, reaction time, and others) to determine the maximum production of biodiesel. It was shown that when the molar ratio of methanol to oil changed from 3:1 to 6:1, the yield percentage increased. Also, the study showed that at 50°C temperature, the yield percentage of biodiesel increased. A transesterification on beef tallow is also reported by Ma et al. (1998). Sodium hydroxide (NaOH) was used as a catalyst, and without the addition of water and free fatty acids, the yield percentage of biodiesel increased. Waste chicken fat and waste fleshing oil have also been reported as test fuels (Alptekin et al.2015). The blend of produced biodiesel with diesel and bioethanol was performed for an engine test. This test was conducted at different loads. The aftermath of this test showed that the brake-specific fuel consumption, which is the parameter to find out the fuel efficiency of a prime over, increased 16.7% than those of diesel fuel. Another parameter that also increased is maximum cylinder gas pressure.

Detailed analysis for biodiesel production from animal fats was reported (Banković-Ilić et al. 2014), particularly concerning minimizing production costs. Biodiesel properties of biodiesel produced from animal fats and poultry fats are compared (Barua et al. 2020b; Chakraborty et al. 2014).

Different transesterification methods and the effects of

different catalysts, temperatures, and pressure were also ana- lyzed. Other reports describe beef tallow and soybean oil as a dual mixture to produce biodiesel blends to study the methyl ester properties of the mixtures (Hossain et al.2020; Teixeira et al.2010). This study attempted to reduce the effects of fatty esters in beef tallow by blending soybean oil with biodiesel produced from beef tallow. The effects can be reduced by using the blending process. Beef tallow is reported as a raw material to produce biodiesel for pilot-scale production (da Cunha et al.2009). At the pilot plant-scale, the process’s economic viability can be improved via recovering glycerin and methanol. To extract biodiesel from beef tallow, some factors such as the availability of raw materials, economic factors, and energy efficiency were considered (Nelson and Schrock 2006). Economic feasibility analysis showed that fuel cost has a significant impact on biodiesel cost. Reports indicate that goat tallow can be used as the main ingredient for biodiesel production (Chakraborty and Sahu 2014). Using an Infrared Radiation Assisted Reactor (IRAR), reduced reaction time, compared to a conventional batch reactor, and higher yield of biodiesel from goat tallow, was achieved. The transesterification process of Silurus triostegus heckel (fish oil) through alkaline catalysts is reported (Fadhil and Ali 2013). The physio-chemical characteristics of methyl ester were found to match with biodiesel standards. A separate extraction machine was designed (Yahyaee et al.2013) to ex- amine fish oil. The produced biodiesel characteristics were compared with biodiesel made with rapeseed and waste cooking oil. For producing biodiesel from different raw materials, evaluation of the purification methods is reported by Mata et al. (2011). Reports describe an environmentally friendly way to produce biodiesel from poultry waste (Purandaradas et al.2018). Alptekin and Canakci (2011) op- timized the transesterification process to produce methyl ester from chicken fat and studied the effects of reaction time and catalyst type on produced methyl ester. Sander et al. (2018) used the chemical transesterification process on different types of animal fat to observe the impact of different purification conditions in obtained biodiesel quality. Seffati et al. (2020) p r o d u c e d b i o d i e s e l f r o m C h i c h e n f a t u s i n g A C / CuFe2O4@CaO. Different reaction variables such as molar ratio, reaction time were changed to observe the optimum biodiesel yield. This study found that the 95.6%

biodiesel could be obtained at a methanol/oil molar ratio of 12:1, the reaction time of 4 h, catalyst concentration of 3 wt%, and reaction temperature of 65 °C. In the study, chicken skin is considered raw material for biodiesel extraction through the catalytic transesterification process. A new model for economic and environmental analysis of biodiesel is also introduced. To our best knowledge, this type of modeling has not previously been reported. The summary of our literature review can be found in Table 1.

Environ Sci Pollut Res

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This study presents the extraction of biodiesel from chicken skin waste products slaughtering houses in Bangladesh. In some developing countries, animals’fat is considered feedstock. Such products are used in poultry farms to produce feather meal, but chicken skin, which contains fat, is generally considered a waste product in Bangladesh (Maidin2014). Another objective is to perform the economic and environmental analysis of biodiesel applications for electricity production in Kutubdia, Cox’s Bazar. These analyses were conducted to demonstrate the effect of using biofuel as fuel on the environ- ment and the economy. Kutubdia is considered an off-grid place. The government has installed a wind battery hybrid power plant in Kutubdia, but the plant does not supply power con- sistently. Electricity is only available for 3 h a day, and people get 3 to 4 h of electricity during nighttime. Only a half percent of people get access to that electricity (Saifullah et al.2016), so a diesel generator is used to meet their electricity demand. In this study, biodiesel is used as a substitute fuel for power generation to determine its environmental and economic viability.

Previous studies have not addressed biodiesel’s environmental, economic feasibility, and sustainability to replace diesel fuel for electricity generation. Also, biodiesel extraction from chicken skin (not fat) using the transesterification process was not done in other studies. It is hoped that this study will serve as an ideal model for the planners of poultry industries to reduce the waste from this sector. It is anticipated that many underdeveloped and developing countries will concentrate their efforts to utilize this waste to produce biodiesel, which can be used as an alternative source of energy generation. Moreover, collection, transportation, processing, and further handling of these kinds of waste may open up future employment opportunities contributing to socio-economic welfare.

Methodology

Raw material collection

Waste chicken skin with the feather was bought from various local shops of Chittagong. The poultry chicken skin with the feather in the slaughterhouses of Bangladesh is not usually processed further for human food. According to the local slaughterhouse owners, the chicken skin with feathers is dumped into a nearby dumping zone. After collection, the skin was manually de-feathered in the kitchen. After de-feathering, the skin was placed in a bowl that contains hot water. This step was done to remove the feather that was attached to the skin thoroughly.

Sample preparation Materials

Chicken skin with different initial mass (200 g, 300 g, and 350 g) is considered raw material. These specific masses of chicken skin have been experimented with based on previous experimental studies’ optimum mass conditions. Then, three runs with different initial mass have been done. The chicken skin was washed with distilled water. Potassium hydroxide pellets (KOH) were used as a catalyst to achieve the high quality of biodiesel, and meanwhile, methanol was used as the solvent.

Methods

The skin (200 g) was then thoroughly washed using tap water and chopped into tiny pieces. Then, the skin was heated for Table 1 Studies on biodiesel

production from animal waste Raw material Process References

Chicken fat Transesterification Awaluddin et al. (2010)

Beef tallow Transesterification Ma et al. (1998)

Chicken fat and waste fleshing oil Blending of produced biodiesel with diesel and bioethanol

Alptekin et al. (2015) Beef tallow and soybean oil Blending of produced biodiesel

with soybean oil

Teixeira et al. (2010)

Beef tallow Transesterification da Cunha et al. (2009)

Beef tallow Transesterification Nelson and Schrock (2006)

Goat tallow Simultaneous transesterification Chakraborty and Sahu (2014)

Fish oil Transesterification Fadhil and Ali (2013)

Waste fish oil Transesterification Yahyaee et al. (2013)

Chicken feather meal Transesterification Purandaradas et al. (2018) Chicken fat and skin Transesterification Seffati et al. (2020)

Chicken fat Transesterification Alptekin and Canakci (2011)

Animal fat Transesterification Sander et al. (2018)

Lamb, poultry, and Swine fatty wastes

Pyrolysis Ben Hassen-Trabelsi et al. (2014)

Environ Sci Pollut Res

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15 min in a pan at 78 °C. The oil sample was then left at room temperature to cool down, taken into a beaker, and measured by an electronic balance. The oil volume was 0.89 ml/g. The stoichiometric molar ratio methanol to oil 6:1 was reacted with KOH through the transesterification process. After dissolving the KOH pellets into the methanol with a glass stirrer’s help, the methanolic KOH solution was poured into the fat sample.

Then, the sample was placed inside the magnetic stirrer appa- ratus. After stirring for 45 min at 60 °C around 1500 rpm, the magnetic bar of the stirrer was taken out by the forceps and washed with methanol.

Then, the stirring sample was placed into a separating funnel for 24 h to separate the layers. Two layers were formed from transesterification, a red and a yellow layer. According to the experiment manual, the red layer was waste glycerol, and the yellow layer was biodiesel (Bharat and Bhattacharya 2012). This glycerol is a valuable by-product and can be sold to earn revenue (Parker2013). The layers were separated manually by controlling the tube of the separating funnel. After separating glycerol, water washing was conducted, and biodiesel was extracted. Then, it was heated to remove residual catalysts or soaps. Then, the produced fuel was shifted to test the fuel’s viscosity and heating value.

Similarly, the other two samples were subjected to transesterification. The amounts required to do these transesterifications are listed in Table2. To calculate the yield percentage of biodiesel, Eq. 1 was used. A saybolt viscometer and a typical bomb calorimeter were used for the viscosity and heating value test, respectively. Table2shows the number of materials involved during the production of biodiesel.

Biodiesel yield from chicken skin¼Weight of biodiesel extracted gð Þ Weight of chicken skin gð Þ

ð1Þ

System modeling

The HOMER Pro software version 3.14 was used for system modeling of chicken skin-based biodiesel application. This software was developed by the National Renewable Energy Laboratory (NREL), United States. Feasibility, techno-

economic, optimization, and sensitivity analyses of stand- alone and grid-connected renewable energy systems were car- ried out using this software (Li et al.2018). In this simulation, an off-grid place, Kutubdia, was considered. Kutubdia (21°

49′N to 91° 51.5′E) is located in the Cox’s Bazar, Chittagong, Bangladesh. Kutubdia, an island, covers an area of 215.79 sq.

km. About 125,279 people live on the island (Myat2018).

In this simulation, basic loads, light-bulbs, fans, and water pumps are considered. The load has been classified as residential load and non-residential load. The simulation has been performed by the HOMER Pro software. There are different versions of Homer available such as Homer Pro, Homer Grid, and Homer beta version. For designing the off-grid system, Homer Pro is an excellent tool. To carry out economic and environmental analysis, the Homer Pro software version 3.14 is used here. Table3presents the assumed residential load and non-residential load for Kutubdia, respectively (Chowdhury et al.2018).

During summer, irrigation pumps are required for agricul- tural activities. Here, in this simulation, a 2 KW irrigation pump was considered. The summer load was considered from March–October, and the winter load was from November– February.

Diesel generator

For optimum sizing of the generator, different ratings of gen- erators were considered. The HOMER Pro software deter- mined the optimum rating of the generator based on the load.

Diesel and biodiesel were used as fuel, and the per KW capital and replacement cost considered here was US$370 and US$296, respectively. The operation and maintenance costs were considered US$0.05 per hour for the generator. An auto- size Genset generator was used in this model. The fuel consumption rate of the diesel generator to generate electricity was simulated by Eq.2.

M ¼M_0;dgYdgþM_1;dg:Pdg ð2Þ

Table 2 Amount of materials involved in the production of biodiesel

Material Chicken skin

Amount of raw material(g) 200, 300, 350

Volume of oil (ml/g) 0.895, 0.928,0.978

Volume of methanol added (mL) 52, 68 ,82 Mass of KOH pellets added (g) 1.79, 1.98, 2.25 Volume of biodiesel produced (mL) 80, 144, 143.5

Table 3 Load description for different non-residential load

Type Load description

Religious institutions 3 CFL (1 CFL=20 watts) 2 Fan (40 watts) College and secondary school 4 CFL (20 watts)

4 Fan (40 watts)

Primary school 2 CFL (20 watts)

2 Fan (40 watts) Bazaars (considering 10 shop in a bazaar) 1 CFL (20 watts)

1 Fan (40 watts)

Madrasah 3CFL (20 watts)

2 Fan (40 watts) Environ Sci Pollut Res